Various rhythm devices for use with electronic musical instruments are well-known. Such devices may be free running, i.e., have their own timing built in, or they may play in time with depression of the musical instrument keys by the musician.
Apparatus for playing arpeggio has also been well-known in the electronic musical keyboard arts. Arpeggios have traditionally been played manually. However, apparatus has also been provided for the automatic playing of arpeggio. See, for example, the copending application of W. R. Hoskinson, Peter Solender, and W. V. Machanian entitled "Accompaniment System for Electronic Musical Instrument", filed Mar. 15, 1978 under Ser. No. 886,750 assigned to the same assignee as the present application, namely The Wurlitzer Company.